298 Prof. M'liitosh's Notes from the 



of the second segment are large. Mature forms liave 

 swimming-bristles. In contrast with M. limbata the colora- 

 tion of this species differs, and the dorsal and ventral cirri 

 appear to be proportionally larger. 



Mystides borealis, Thoel, from the west coast of Ireland 

 {Souiheni), is another of the minute examples (5^ mm. 

 long) of the genus, which can best be studied in the living 

 condition, and it is possible that revision may alter certain 

 of the views at present held. Southern's careful descrip- 

 tions, however, will aid materially in their elucidation. 

 The broadly oval cirri of this form are conspicuous. The 

 bristles are slender and of moderate length {Southern). 



Mystides elongata, Southern, is a remarkably elongate 

 Irish form, with long setigerous processes, long segments, 

 and peculiar bristles. The head is twice as long as broad, 

 and has two eyes devoid of lenses in the postero-lateral 

 angles. The body is minute (6 mrn.) and has 80 seg- 

 ments. The colour is yellowish or dark green. The first 

 segment has a single pair of long tapering cirri, the second 

 has two pairs, but there are no traces of spines or bristles. 

 The third segment has a setigerous lobe and a ventral cirrus. 

 The setigerous lobe generally is bluntly pointed, and has a 

 spine and four bristles, whilst the dorsal cirri are small 

 and fusiform; ventral cirri longer. Three of the bristles in 

 each foot are compressed, the shaft being thick, curved, 

 bevelled (but not swollen at the tip), and bifid. Mature 

 females have bluish-gieen eggs [Southern). 



In Oxydromiis propinquus, Marion and Bobretzky, from 

 the west coast of Ireland [Southern) ., one of the Hesionidae, 

 the head is somewhat cordate in outline, broad posteriorly 

 where the dimple is, nearly straight at the narrower anterior 

 end, and having four eyes in a trapezoid about the middle, 

 the anterior pair being bean-shaped, larger, wider apart, and 

 furnished with lenses. The median tentacle is short and 

 slightly fusiform, the lateral more than twice as long, a 

 little tapered toward the tip, and separated from the rest 

 of the head by a ciliated depression. The palpi have two 

 articulations, a basal and a longer distal. Four tentacular 

 cirri occur on each side, the largest and longest being the 

 posterior dorsal, and in each a nerve is distinct. The pro- 

 boscis, which has a minutely papillose surface, is of a bright 

 orange hue, and extends to the fifth setigerous segment. 

 Anteriorly it has a series of serrated papillae. It is followed 

 by the intestine, which is constricted at each dissepiment. 

 The body varies in length from 6-10 mm., is typical in out- 

 line, and terminates posteriorly in two long articulated anal 



